A method for manufacturing a semiconductor device, comprising the steps of:
- (a) providing a semiconductor substrate that includes a first main surface and a second main surface opposing the first main surface, and includes a first semiconductor region of a first conductivity type at least on the second main surface side;
- (b) forming a first trench, a second trench that is arranged so as to be apart from the first trench, and a third trench that is arranged so as to be apart from the second trench, the first trench, the second trench, and the third trench reaching the middle of the semiconductor substrate;
- (c) forming a first conductive film over the semiconductor substrate including the inside of the first trench, the second trench, and the third trench through a gate insulating film;
- (d) forming a first gate electrode in the inside of the first trench through a first gate insulating film, forming a second gate electrode in the inside of the second trench through a second gate insulating film, and forming a third gate electrode in the inside of the second trench through a third gate insulating film by etching the first conductive film, and forming a coupling section that couples the second gate electrode and the third gate electrode with each other;
- (e) forming a second semiconductor region of a second conductivity type that is opposite to the first conductivity type on the first main surface side of a first region between the first trench and the second trench and a second region between the second trench and the third trench;
- (f) forming a third semiconductor region of the first conductivity type within the second semiconductor region of the first region so as to come in contact with the first gate insulating film;
- (g) forming an interlayer insulating film over the first region and the second region;
- (h) forming a first opening that comes in contact with the third semiconductor region by etching the interlayer insulating film;
- and
- (i) forming a first electrode by forming a second conductive film over the interlayer insulating film including the inside of the first opening,
- wherein, in the step (c), the first trench, the second trench, and the third trench are formed so as to extend in a first direction,
- wherein, in the step (d), the coupling section is formed so as to extend in a second direction that crosses the first direction, and
- wherein, in the step (h), the first opening is formed so as to be divided in a crossing region of extending directions of the first region and the coupling section and to include a first section that is arranged on one side of the crossing region and a second section that is arranged on the other side of the crossing region in the first region, and the first opening is not arranged in the crossing region.